In patients with CD4 counts ≤100 cells/μL and VL <400 copies/mL, there were 4 episodes of PCP over 104.2 person-years follow-up PYFU, for an event rate of 3.84 events per 100 PYFU (95% CI, 1.05, 9.83) [14]. Here, CD4 is linked to pneumocystosis.